Apparatus for inspecting sheets



@En 21, 1950 A. E. KADELL. 2,501,224

APPARATUS FOR INSPECTING SHEETS Original Filed March 51, 1945 l2 Sheets-Sheet l K mtorneg A. E. KADELL APPAR'I'US FOR INSPECTINC- SHEETS 2 Sheets-Sheet 2 Original Filed March 5l, 1945 Patented 1,1950

UNITED STATES PATENT OFFICE amaai Y Aurea E. malen,` Steubenville, om, umm to National Steel Corporation, a corporation of Delaware Original application March 31,Y 1945, Serial No. 585,988. Divided and this'application June 17, 1947, Serial No. 755.183

1 'Ihis invention relates toiapparatus for inspectlng sheets, for example, tin plate, and more par- 4 claims. (ci. 19a-s3) tlcularly relates to such an apparatus for successively turning the sheet to permit visual kl,inspection of the opposite faces of each sheet.

This application is a division of my copending application Serial No. 585,988,V flied March 3l, 1945, for Apparatus for inspecting and sorting sheets.

In the manufacture of tin plate, sheets are produced of different grades and the sheets must be inspected and sorted into, for example, three groups comprising prime sheets which are substantially free from aws; "menders which contain inperfections but which can be salvaged by reprocessing or other treatment; and scrap which,

is detinned. Such sheets often are inspected by workers who manually turn each sheet to inspect both sides and'then sort the sheet into piles according to grade. Machines have been used to a certain extent to inspect such sheets but in general, these machines are relatively complicated and expensive and are often difficult to operate.

While the present invention will bedescribed in connection with inspecting and sorting tin plate, the invention is not limited to Such material and can be'used for inspecting and sorting sheets of other materials such as steel, paper and the like.

It is an object of this invention to provide an improved machine for rapidly andaccurately inspecting a succession of sheets; to provide such a machine which includes an improved mechanism for turning and exposing both sides of the sheet to view for inspection; to provide sucha machine including improved control means; and to provide such a machine which is economical to construct and which can be operated by one person.

The present invention provides a machine including a conveyor for delivering a succession of single sheets to a, turning mechanism which turns and exposes both sides of the sheets to view and which is automatically operated by movement of a sheet into position to be turned. The sheets-are successively moved away from the turning mechanism along a path and means are provided for selectively grouping the sheets according to quality.

These and other objects `and advantages will become more apparent from the following detailed description taken with the accompanying drawings, in which:

Figures 1-A and l-B together are a plan view of a machine embodying the principles of the present invention:

. 2 l Figures 2-A and 2B together are aside elevational view oi' the machine of Figures 1-A and Figure 31s a schematic representation of means for controlling the operation of the sheet turning mechanism oi' the machine of Figures l-A and l-B; and A, i

Figure 4 is a schematic representation of the control means for operating one of the sheet sorting dflectors of the machine of Figures 1A and l-B.

Referring to the drawings which show a preferred embodiment of the invention, the apparatus comprises a conveyor F for successively feeding a plurality of single sheets of the same and different grades of tin plate to a sheet turningmechanism T which turns and exposes both sides of each sheet for inspection. After being inspected, the sheets are deposited on a second conveyor `C which moves them away from the mechanism T and along a path. Both of the conveyors F and -C and the sheet turning mechanisrn T are driven by a single electric motor M. Two deectormechanisms X and Y are interposed between sections of the conveyor C for selectively deilecting sheets of certain grades from their normal path of movement', and are controlled by the operator while located adjacent the turning mech anism T and in position to observe the quality of the sheets as they are turned. The sheets may be successivelyA fed onto the conveyor F by any suitable sheet feeding apparatus, not shown, or the sheets may be placed on the conveyor F by hand, though manually feeding the sheets is undesirable because of the additional labor required. The positioning of conveyor F at the discharge end oi' a tinning and branning machine, in the case of h-ot dip tin plate, or at the discharge end of a shearing line, in the case of electrolytlc tin plate, will result in the most economical handling of the plate. y The conveyor F is supported by the machine frame I0 and includes three spaced, relatively narrow belts II, all of which extend about a singie wide roll I2 mounted on a shaft I3 rotatably supported in. bearings I4 on base I0. The oppo-` site end of each of thebelts I I extends about a separate, relatively narrow, corresponding roll I5 mounted on a shaft I6 supported in a pair of bearings Il on frame I0. A sprocket I8 mounted on they shaft of motor M is connected to a sprocket 20 keyed to shaft I3 by a chain I9 so that as the motor M rotates in a counter-clockwise direction, the shaft I3 rotates in the same direction to move a sheet placed on the belts II of conveyor F ascuas 3 toward the left to the sheet turning mechanism T.

'I'he sheet turning mechanism T is intermittently rotatable and comprises a shaft 22 having fastened thereon two spaced sheet holders 22, each of which includes a hub portion and'six radially extending arms 24 spaced apart 45j'. The radial arms 24 extend between belts Ii and two of the radial arms are so positioned as to receive a sheet moving along the conveyor F. The shaft 22 is rotatably mounted in a pair of bearings 2l on the frame i8. A slip clutch 28 is mounted on and connected to shaft 22 and one side of the slip clutch 28 is fastened to a sprocket 21. The sprocket 21 is not directly connected to shaft 22 and is connected by chain 28 to sprocket 28 on shaft 8|. Shaft 8| is connected by sprocket 88 and chain 82 to sprocket 88 on shaft 34 which has a sprocket 85 mounted on its opposite end and connected through chain 28 to sprocket 81 on the shaft of motor M. Normally the motor M runs continuously and continuously applies torque through the slip clutch 28 to the shaft 22. The amount of torque tending to turn shaft 22 and holders 28 can be varied by adjusting slip clutch 28.

Referring more particularly to Figures l-A, 2-A and 3, the means for controlling the intermittent rotation of the turning mechanism comprises a ratchet-shaped cam 40 with four notches 4I that is connected to shaft 22. Normally, the lower end of a rod 42 engages one of the cam notches 4I and serves as a pawl to prevent turning of shaft 22. The rod 42 is connected to a solenoid 43 which is energized by the closing of switch 44 to raise the rod 42 and permit shaft 22 to rotate in a counterclockwise direction. The switch 44 is so positioned that when a sheet is moved by belts i I into position to be raised by a pair ofthe radial arms 24, the sheet engages the switch 44 to close the switch and energize solenoid 48 to release the cam 40.y As the shaft 22 starts to turn, the holders 23 move the sheet upward and away from switch 44 which permits it to open and de-energize solenoid 43 so that the rod 42 drops down and the lower end rides on one of the four smooth surfaces 45 until the rod engages the next notch 4i after the shaft 22 has rotated 90. When the holders 23 and shaft 22 turn 90, the sheet is turned on edge and the momentum causes the sheet to tip over against the next pair of radial arms 24 so that actually each sheet turns 135 instead of 90 which permits easy inspection of the sheet. When the next successive sheet engages switch 44, the shaft 22 again turns and deposits the rst sheet on the conveyor C after rotating through about 45 and turns the second sheet through about 135, as previously described.

The conveyor C comprises three sections and the first section includes three spaced belts 41 which extend about two relatively wide rolls 48 and 49. Roll 48 is mounted on shaft 50 rotatably supported in bearings i and roll 49 is mounted on shaft 52 rotatably supported in similar bearings on frame I0. The opposite end of each belt 41 extends about a separate, relatively narrow, corresponding one of three rolls 53, each of which is mounted on a shaft 54 rotatably supported in a pair of bearings 55. A sprocket 55 on shaft 52 engages chain 51 which is driven by sprocket 58 on shaft 59. A second sprocket 80 keyed to shaft 59 engages a chain 8| which is driven by sprocket 82 on shaft 94. Shaft 34 is driven by the motor M in the manner hereinbefore described so that as the motor M rotates in a counterclockwise direction, sprocket 58 rotates in a similar direction.

The second section of the conveyor C includes three belts 84 extending about three similar, relatively wide rolls 88 each of which is mounted on a shaft 88 rotatably supported in a corresponding pair of bearings 88 on frame I8. A sprocket 81 is mounted on one of the shafts 88 as is shown more clearly in Figures l-B and 2-B. The sprocket engages the chain 81 and is driven by the motor M. The third and last section of the conveyor C comprises three belts 18 extending around three similar rolls 1 I, each rotatably mounted in bearings 12 on frame i0. Sprocket 13 is mounted on one of the shafts-of one of the rolls 1| and engages the chain 51 so that the motor M rotates the sprocket 12 and drives the belts 10.

Additional similar sections can be added to conveyor C or the number of sections can be reduced depending on the number of grades into which the plates must be sorted, all as more fully hereinafter described.

Between the first and second sections of the conveyor C there is provided a deilector mechanism X which can be tilted to deect a sheet moving along the conveyor C downwardly between the sections of the conveyor into a pile or container therebelow or which can be positioned, as shown more clearly in Figures l-B and 2-B, to permit the sheet to continue along the conveyor C. The deflector mechanism X comprises a blade 15 mounted on a shaft 18 supported in bearings 11 on frame lll.` An arm 18 is mounted on one end of the shaft 18 and is connected to the lower end of a rod 19 of solenoid 80. Solenoid 80 is connected through wires 8l to a push button switch 82 which is connected to a source of electric current and which is located so as to be readily accessible to the operator standing at the inspection station. When the push button 82 is closed. the solenoid is energized to lift the deflector blade 15 and deflect a sheet or sheets moving along on the belts 41 downwardly between the first and second sections of the conveyor. When the push button 82 is released, the solenoid 80 is deenergized and the defiector blade 15 returns to the position shown in the drawing to permit movement of a sheet along the conveyor C and its path of travel without interference.

The deflector mechanism Y, which is located between the second and third sections of the conveyor C, comprises a deiiector blade 83 mounted on shaft 84 supported in bearings 85 on frame I8. An arm 86 is fastened to shaft 84 and is also connected to the lower end of rod 81 of solenoid 88. The solenoid 88 is connected by wires 89 to a time delay mechanism 90, as shown diagrammatically in Figure 4. The adjustable time delay mechanism 90 is connected by wires 9| to a. source of electric power and is also connected through wires 92 to a push button 93 located adjacent push button 82. The time delay 90 includes a switch arm 94 extending toward a square cam 95 on shaft 22, and is so constructed and arranged that the end of the arm 94 is moved to close a switch in the mechanism 90 by movement of a corner of the cam 95 into engagement with the arm 94. It is only when the switch 93 is closed and when a corner of the cam 95 engages the switch arm 94, that the circuit to mechanism 90 is completed. When the operator manually closes switch 93 and when the shaft 22 rotates to deposit the inspected sheet on the first section of the conveyor C, the time delay mechanism 90 is energized and after a predetermined period, which is the period required for a sheet to travel along on belts 48 and 84 to the deilector mechanism Y from the turning mechanism T, the solenoid 88 is energized for a brief period to raise the deflectorblade 83 so that the sheet is deflected downwardly between the from the turnover mechanism T to the deflector mechanism Y and will only deflect one sheet unless the operator continues to press button 93 to deflect more than one sheet.

Any suitable time delay mechanism may be used and my invention is not limited to a particular type of relay. The time delay means may be similar to that shown and described in United States Patent No. 2,217,342, issued October 8, 1940 to A. G. Ladrach. The purpose of time delay means 90, or its equivalent. is to cause thev deector mechanism Y to be actuated after the control switch 93 is closed and a period after the sheet has been deposited on the conveyor C, this period being equal to the time required for a sheet to move from the turning mechanism to the defiector Y. Without the time delay means, the deilector mechanism Y would tend to deflect sheets other than the one which the operator intended to deflect.

When sheets are being sorted, the operator stands within reach of the push button switches 82 and 93 and in position to readily observe the sheets as they are successively turned to expose both sides of each for inspection after being fed one at a time onto the right hand end of the conveyor F. When each sheet is moved into position above two of the horizontal, radial arms 24 extending between belts i l, the sheet engages switch 44 to close it and energize solenoid 43 whereupon the shaft 22 turns to raise the sheet. As the sheet is raised, switch 44 opens and the previously mentioned horizontal, radial arms move the sheet to the vertical position where the momentum causes it to flop over where it is supported by the next pair of radial arms 24 so that the operator can readily inspect the bottom surface of the sheet. The next sheet moving along conveyor F causes the turning mechanism to turn another 90 and turn this next sheet 135, as previously described. The first sheet is deposited on the belts 41 of the iirst section of the conveyor C after the turning mechanism has rotated through 45. If the first sheet is scrap, the operator presses button 82 as the sheet is deposited on the belts 41 to energize solenoid 80 and raise the defiector blade 11 so that the sheet, after moving along on belts 41, strikes blade 11 and is de flected downwardly between the first and second sect-ions of the conveyor. If the sheet is a menden then the operator presses switch button 93 and when the turning mechanism rotates 45 so that switch arm 90 is actuated by cam 95 and the sheet is deposited on conveyor C, the circuit for time delay mechanism 90 is closed. The operator can release switch button 93 after the sheet has been deposited on the conveyor C. The sheet then moves along the conveyor C and approaches the defiecting mechanism Y and the time delay 90 automatically energizes solenoid 88 to tilt the deflector blade 83 upwardly at the proper moment so as to deflect the sheet downwardly betwen the second and third sections of the conveyor C. If the tin plate is a prime sheet, the operator does not press either one of the switches 89 or 93 and the plate moves along the conveyor C to the end of the conveyor where it is stacked with the other prime sheets. Thus. the

operator can readily inspect both sides of the sheets and can readily sort them into groups according to grade.

Any suitable type of containers may be pro-v vided beneath the turning mechanisms X and Y and at the end of the conveyor C for receiving and stacking the sheets in condition for transportation to other locations.

Having described a preferred embodiment of my invention in detail, it is to be understood that various modifications may be made therein and that some features may be used without others,

all without departing from the spirit and scope of my invention except as set forth in the accompanying claims.

I claim:

1. Apparatus for lifting and turning a series of sheets successively delivered vto a position to be turned comprising arotatable shaft; sheet supportlng'arms on said shaft foi` lifting and turn-ing a'sheet upon rotation of said shaft; and power actuated means for intermittently rotating said shaft, said means including a slip clutch having one side connected to said shaft, a continuously operating motor connected to the other side of said slip clutch for continuously applying a torque to said shaft, a notched ratchet member operatively connected to said shaft and rotatable therewith, a releasable pawl normally urged into engagement with a notch of said ratchet member to prevent rotation of said shaft and ratchet member, and switch control means operatively connected ,to said pawl and located so as to be engaged' by' a sheet when in the position to be turned and located so that the sheet is moved out of engagement with it upon being lifted from said position, said control means being operable when engaged by a sheet to move said pawl out of engagement with said ratchet member and permit rotation of said shaft and the lifting and turning of the sheet and then operable upon lifting of the sheet to permit the return of said pawl to engaging position with respect to said ratchet member.

2. Apparatus for lifting and turning a series of sheets successively delivered to a position to be turned comprising a rotatable shaft; sheet supporting arms on said shaft for lifting and turning a sheet upon rotation of said shaft; and power actuated means for intermittently rotating said shaft, said means including a slip clutch having one side connected to said shaft, a continuously operating motor connected to the other side of said slip clutch for continuously applying a torque to said shaft, a ratchet member connected to and rotatable with said shaft and having a plurality of notches4 disposed about its peripheral portion with cam surfaces therebetween, a pawl normally urged toward and into engagement with the peripheral portion of said ratchet member, said pawl being engageable with a corresponding one of the notches to prevent rotation of said ratchet and being engageable with a corresponding one ofA said cam surfaces to permit rotation of said shaft and ratchet member f engagement with it upon being lifted from said position, said switch being operable when engaged by a sheet to withdraw said pawl from engagement with said peripheral portion and the corresponding one of said notches and permit rotation of said shaft and the lifting and turning of said sheet and operable upon raising of the sheet to permit return of said pawl into engagement with said peripheral portion and a corresponding cam surface of said ratchet member whereby said shaft rotates until the next notch'is moved into the pawl-engaging position.

(3. Apparatus for lifting and turning a series of sheets successively delivered to a position to be turned comprising a rotatable shaft; sheet sup- 'porting arms on said shaft for lifting and turning a sheet upon rotation of said shaft; and power actuated means for intermittently rotating said shaft in increments of 90, said means including a slip clutch having one side connected to said shaft, a continuously operating motor connected to the other side of said slipA clutch for continuously applying a torque to said shaft, a ratchet member on said shaft and connected thereto, said ratchet member having four notches spaced 90 apart about its peripheral portion with cam surfaces extending therebetween, a pawl engageable with the corresponding one of said notches to prevent rotation of said shaft and ratchet member and engageable with a corresponding one of said cam surfaces to permit rotation of said shaft and ratchet member, said pawl being so located adjacent said ratchet member that rotation of said ratchet member successively moves said notches and cam surfaces past engaging position with said pawl and said pawl normally being urged toward said ratchet member and into engagement with the corresponding one of said notches and cam surfaces, solenoid means for moving said pawl out of engagement with said ratchet member, and a switch operatively connected to said solenoid means and located so as to be engaged by a sheet when in the position to be turned and located so that the sheet is moved out of engagement with it upon being lifted from said position, said switch being operable when engaged by a sheet to energize said solenoid means and cause it momentarly to move said pawl out of engagement with said ratchet member to permit said shaft to turn and lift the sheet and operable upon lifting of the sheet out of engagement with the switch to de-energize said solenoid means and permit return of said pawl into engagement with the corresponding cam surface of said ratchet member whereby said shaft rotates through 90 until the next notch is moved into the pawl-engaging position.

4. Apparatus for lifting and turning a series of sheets successively delivered to a position to be turned comprising a rotatable shaft; sheet lifting arms on said shaft angularly, equally spaced apart a predetermined number of degrees for successively lifting and turning successive sheets from the position to be turned upon rotation of said shaft; and power actuated means for intermittently rotating said shaft, said means including a slip clutch having one side connected t0 said shaft, a continuously operating motor connected to the other side of said slip clutch for continuously applying torque to said shaft through said slip clutch, a ratchet member connected to said shaft and rotatable therewith, said ratchet member having notches about its periphery angularly spaced apart the same number of degrees as said sheet lifting arm, a releasabla pawl, means normally urging the pawl into engagement with a notch of said ratchet member to prevent rotation of said shaft and the ratchet member, and switch control means operatively connected to said pawl and located so as to be engaged by a sheet when in the position to be turned and located so that the sheet is moved out of engagement with it upon being lifted from said position by one of the lifting arms, said control means being operable when engaged by a sheet to move said pawl out of engagement with the ratchet member notch and permit rotation of said shaft by said motor and the lifting and turning of the sheet and then operable upon lifting of the sheet to release the pawl to permit the return of said pawl to engaging position with respect to said ratchet member whereby the next following notch is engaged by the pawl to stop the shaft when the next lifting arm is moved into position to lift the next successive sheet from the position to be turned.

ALFRED E. KADELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,195,571 Flaherty Aug. 22, 1916 1,970,749 Heichert Apr. 21, 1934 2,000,292 Miller May 7, 1935 Certcate of Correction Patent No. 2,501,224 March 21, 1950 ALFRED E. KADELL It is hereby certified that errer appears in the printed specicaton of the above numbered patent requiring correction as follows:

Column 5, line 60, for switch arm 90 read switch arm 94;

and that the seid Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Ofice. Signed and sealed this 22nd day of August, A. D. 1950.

THOMAS F. MURPHY,

Assistant Gommz'sszaner of Patents. 

